Maybe it's more about technique, or method, than product? Try clipping up your roots with duckbill clips while they dry, or gently hold your roots up while blasting a shot of heat at them...or, blowdry your hair upside-down..or, use the "rocker" headshake - bend at the waist, then shake your hair around...

Or check out the "techniques" sticky on the top of both the newbies' and the general hair discussion forum. There are many there that may help you

You can also "pineapple" (put your hair in a ponytail at the very top crown of your head) your hair at night, as you sleep - next day you will have great root volume...if none of those things work, then maybe your problems are stemming from products that worked well during summer, when everything is humid, that don't work well in the dry winter ;p hoped that helped, and good luck!

There are loads of far more experienced curly people here, and no doubt they will chime in